1. Field of the Invention
The apparatus of the present invention relates to indicators with lenses. More particularly, the apparatus of the present invention relates to an indicator with lens for indicating changes in a system of variables by reflecting, refracting and dispersing particular information provided in a band on an internal stem through the top surface of the lens body.
2. General Background of the Invention
In various aspects of industrial and commercial uses, very often there is utilized a viewing lens to indicate to a viewer, or a person whose duty it is to monitor an indicator, the status of a particular system by color changes as viewed in the lens. For example, a standard commercial use of a viewing lens is a rotary type channel selector on a television set, wherein the selected channel number is viewed on the face of the indicator, normally through an internal light source, so that the person attempting to select a particular channel is able to read the channel number as it visually appears on the indicator.
In a common industrial use, indicators have been utilized on certain types of valves, in most cases, a relay valve, wherein the valve is variable between an open and shut position, the open position allowing flow of fluids through the valve to an actuator in order to allow an oil well or the like to continue in production. Should there be a failure in the system, the relay would "shut-in" due to a change in a measured quantity, and the valve would shift from an open to a closed position. By necessity, these valves are constantly monitored, so that when the valve does shift from open to closed, or closed to open, the operator of the system is aware of the shift in the valve, and the status of the system at that point. Of course, in order to facilitate an operator in knowing when a valve is in the open or closed position, a type of indicator has been used throughout the years, in oder to assist in that determination. What has become standard in the industry, is the use of a color-coded indicator, wherein "green" would signify the valve is in the open position, and "red" would signify the valve is in the closed position, thus indicating a problem in the system, and that the system is "shut-in".
One type of indicator that has been utilized has been the "Winkie" indicator, which is a rotary type of indicator with a spherical surface half green and half red such that when the valve is in the open position, the rotary ball or sphere of the indicator has been shifted so that the green color is apparent exterior to the valve, and a viewer simply looks at the rotary ball and the color green indicates that the system is in normal operation. Likewise, when flow is interrupted through the relay valve, the ball shifts back to the red half of the sphere, and the red is indicted exterior to the valve, thus the operator on viewing red, knows that the system has shut-in.
Since this particular type of "Winkie" indicator requires the mechanical manipulation of a rotary ball within the valve, often times the indicator ball is quite inefficient in indicating a true reading of the valve state, and therefore has led to problems. In order to overcome these problems, a different type of indicator has been utilized wherein the valve provides an internal stem which moves longitudially within a bore in the valve so that internal pressure on the end of the stem provided with a piston would move the stem to an "up" position, and the loss of pressure on the same end of the stem would move the stem back to the "down" position. The head of the stem is provided with green and red bands of color which when shifted from the "down" to the "up" position, the red or green band of color respectively will appear through a lens provided at the top of the valve for indicating the position of the valve. In order to give the operator a better view of the red or green color indication, a type of "lucite" or plastic lens has been used which is a knob-type of indicator having a flat surface wherein the internal red or green color on the stem would be reflected, refracted and dispersed in such a way that a band of red or green respectively would appear through the top portion of the lens body, and thus give the reader a better read-out of the color. However, one of the shortcomings in this particular type of indicator lens is that the band of color on the stem, due to the shape of the indicator lens, is not properly reflected, refracted and dispersed so that a clear reading of the color indicated can be obtained. Therefore, should the operator be in a position not directly above the lens' upper or viewing surface, then he could observe a false reading of the operating state of the valve, which could lead to significant problems in the maintenance of the valve and system.
Several patents have been obtained which address the use of indicators in various fields of art, and these are as follows:
U.S. Pat. No. 2,711,711 issued to E. I. Harman entitled "Tuning Apparatus" teaches the use of a reflective lens for more properly viewing indicia on a television knob. In FIG. 2 thereof is illustrated a prism-type lens having an interior angulated surface and an exterior angulated surface, the combination of which readily reflects light originating from within the apparatus. However, this patent also teaches the use of an internal light source for projecting light onto the lens' surfaces and for the reflection of a particular number of the lens face rather than a band of color.
U.S. Pat. No. 3,636,915 issued to Ruppert entitled "Rotary Prism Display" teaches the use of an angulated internal translucent prism for illuminating images on a knob, particularly in the use of rotary control knobs and the like. This patent only shows one angulated surface, for receiving light from an internal source within the mechanism or from ambient room lighting.
U.S. Pat. No. 2,172,316 issued to D. O. Sproule entitled "Indicating Instrument" also shows a singular angulated surface and an internal light source.
U.S. Pat. No. 2,616,941 issued to G. A. Lasko entitled "Indicating Apparatus" also teaches the use of a reflective lens for reflecting the light and an indicating means within the lens. This particular indicator is used primarily on a battery to show fluid levels and does not teach the use of a double angulated lens as in the present invention.
The patents listed below also were found in the art, and are less pertinent to the particular invention:
______________________________________ U.S. Pat. No. Inventor Title ______________________________________ No. 1,883,971 Kryzanowsky "Signaling Device" No. 3,041,917 Glatt "Underwater Instrument Viewing Device" No. 2,566,789 Blackinton, "Optical Sight Means For et al Indicating the Level of Liquids or Other Reflec- tive Surfaces" No. 2,334,479 Creager "Tell-Tale Device" No. 3,899,187 Kisselmann, "Indicating Instrument" et al ______________________________________